The application of saturable turn-on snubbers to IGBT bridge-leg circuits

Finney, S.J.; Tooth, D.J.; Flethcer, J.E.; Williams, B.W.

doi:10.1109/63.803404

Cited by 14 publications

(6 citation statements)

References 12 publications

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“…The LRCD snubber network [{L, R, C, D} X ± in Fig. 6(b)] substantially reduces IGBT turn-on and turn-off switching losses by zeroing the device voltage during transitions for ∼1 μs [14]. This permits each phase to operate at ∼30 kHz for a 0.1-s pulse.…”

Section: Zero-voltage-switching Resonant Convertermentioning

confidence: 99%

Digital Control and Power Systems for the Pegasus-III Experiment

Bongard

Borchardt

Diem

et al. 2022

IEEE Trans. Plasma Sci.

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The PEGASUS-III experiment is a solenoid-free, low aspect ratio spherical tokamak that will serve as a dedicated U.S. platform for comparative nonsolenoidal tokamak plasma startup studies. Approximately 175 megavolt-ampere (MVA) of reconfigured and expanded programmable power systems, 7 MJ of new stored energy, and new digital control and protection systems for the facility are being commissioned to support PEGASUS-III upgrades. These include: increased toroidal field (0.15-0.6 T); new divertor and poloidal field coils; increased pulse length; local and coaxial helicity injectors for solenoid-free plasma initiation; radio frequency (RF) systems for heating and current drive; and a diagnostic neutral beam (DNB). A new realtime digital control system implements 16 proportional-integral differential (PID) feedback controllers with 25 kHz loop rates to control the electromagnets and helicity injectors. The poloidal field coils, helicity injector arc currents, and toroidal field are driven by 36 3.6 MVA (4 kA, 900 V) insulated-gate bipolar transistor (IGBT) buck converters. Helicity injector bias voltage and current will be provided by a set of four 10.8 MVA multilevel buck converters (MLBCs). Each is comprised of an 1800 V integrated gate-commutated thyristor (IGCT) stage and a ±900 V IGBT stage in series, providing controllable I inj ≤ 4 kA at V inj ≤ 2.7 kV. A field programmable gate array (FPGA)-based digital fault protection system multiplexes controller commands to individual power semiconductors in these supplies, monitors their operational status, and executes shutdown sequences within 10 µs of fault detection. An 80 kV, 4 A zero-voltage-switching (ZVS) resonant converter with <1% output ripple is under development for the DNB and is being evaluated as a topology to drive RF sources.

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Section: Zero-voltage-switching Resonant Convertermentioning

confidence: 99%

Digital Control and Power Systems for the Pegasus-III Experiment

Bongard

Borchardt

Diem

et al. 2022

IEEE Trans. Plasma Sci.

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“…where T d5 is given by (13). The switch S 1 must be on from t = t 0 at least till t = t 3 when I Ls becomes zero.…”

Section: Advances In Power Electronicsmentioning

confidence: 99%

“…Although, synthesis and optimization of various snubbers have been widely reported in the literature for low power dc-dc converters [1,5,6,[9][10][11][12][13][14][15][16][17][18][19], the issues related to design, optimization, application, and practical aspects pertaining to their use in high power dc-dc converters are not reported. This paper presents the design and optimization of energy recovery snubber with wide operating range for high power dc-dc converters.…”

Section: Introductionmentioning

confidence: 99%

“…rise of current in the main switch at turn-on transient and thereby achieving zero current switching (ZCS) at turn-on transient of the switch [8,13], while turn-off snubbers are nondissipative voltage snubbers which control growth rate of voltage across the switch during turn-off transient and thus help in achieving zero voltage switching (ZVS) at turnoff transient [8,[14][15][16][17]. The combined function snubber, also called as turn-on and turn-off snubber, serves the dual function of achieving ZCS turn-on and ZVS turn-off of the switch during turn-on and turn-off transients, respectively, and hence includes the functionality of both turn-on and turn-off snubber in a single circuit [5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Development of High Power DC-DC Step-Down Converter with Energy Recovery Snubber

Singh

Borage

Tiwari

et al. 2012

Advances in Power Electronics

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The effect of switching losses on the efficiency of a switch mode power converter and methods adopted for its improvement using an energy recovery lossless snubber has been presented. A comparative analysis of various types of soft switching techniques along with effects of dissipative and nondissipative snubbers on efficiency of the converter has been carried out before zeroing in on the selected scheme. The selected snubber serves the dual function of a turn-on and turn-off snubber and thereby reducing the switching losses both during turn-on and turn-off transients, resulting in improved efficiency of the converter. A detailed design procedure of the snubber for high-power applications taking into account various effects such as diode reverse recovery, diode voltage stress, and minimum and maximum duty cycle limits, has been presented in this paper. Importance of practical aspects in layout to minimize wiring inductance is also highlighted. A high-power prototype of buck converter has been developed to experimentally validate the theoretical design and analytical observations.

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“…When M 1 is turned off and M 2 is turned on, saturable inductor L s begins to releases its stored energy through clamping diode D b and boost diode D o to the output. In general, the blocking time T B can be estimated as follows [5]:…”

Section: Analysis and Design Of The Proposed Boost Convertermentioning

confidence: 99%

An improved boost converter with coupled inductors and buck-boost type of active clamp

Lai

Hung

et al.

Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005.

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This paper proposes an improved boost converter with coupled inductors and buck-boost type of active-clamp feature, PWM control and zero-voltage switching in both main and auxiliary switches. In the converter, the active-clamp circuit is used to eliminate voltage spike induced from the leakage inductor of the coupled inductors. The active switch of the converter can still sustain a proper duty cycle when it operates with a high stepup voltage ratio, reducing voltage stress significantly. A set of passive-clamping circuit is adopted to eliminate undesired resonance between leakage inductor of the coupled inductors and stray capacitor of the boost diode, recovering trapped energy. Thus, conversion efficiency can be improved significantly. A 200 W prototype of the proposed boost converter was built from which experimental results have shown that efficiency can reach as high as 92% and surge can be suppressed effectively. I. INTRODUCTIONIn a boost converter with coupled inductors, the active switch can sustain proper duty cycle while operated with high step-up voltage ratio, reducing voltage stress significantly. However, leakage inductor of the coupled inductors would induce voltage spike which results in high component stress, low conversion efficiency and high noise level. A resistorcapacitor-diode snubber can alleviate voltage stress of the switch, but the energy trapped in the leakage inductor is dissipated. A boost converter with active clamp and pulse width modulated (PWM) control can result in zero-voltage switching (ZVS) in both main and auxiliary switches, which makes the converter more viable. Additionally, leakage inductor of the coupled inductors can limit the decreasing rate of the boost-diode current, reducing diode reverse-recovery loss.

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The application of saturable turn-on snubbers to IGBT bridge-leg circuits

Cited by 14 publications

References 12 publications

Digital Control and Power Systems for the Pegasus-III Experiment

Digital Control and Power Systems for the Pegasus-III Experiment

On the Development of High Power DC-DC Step-Down Converter with Energy Recovery Snubber

An improved boost converter with coupled inductors and buck-boost type of active clamp

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